WO2010018335A1

WO2010018335A1 - Device and method for the ultrasound monitoring, measuring, and tracking of heat-sealed seam between two metal parts

Info

Publication number: WO2010018335A1
Application number: PCT/FR2009/051522
Authority: WO
Inventors: Sébastien REVOIRARD; Emmanuel Futin
Original assignee: Areva Np
Priority date: 2008-08-13
Filing date: 2009-07-29
Publication date: 2010-02-18
Also published as: FR2935050A1; US20110209547A1; FR2935050B1

Abstract

The invention relates to a device for the ultrasound monitoring, measuring, and tracking of a heat-sealed seam between two metal parts, including at least one ultrasonic transceiver (15). The device includes a pad (11) having a planar surface (12) capable of contacting a wall of one of the two parts and comprising a recess (13) for retaining the ultrasonic transceiver (15) along a predetermined direction relative to said wall, an ultrasonic transceiver (15) cooling means having a temperature lower than the boundary operating temperature thereof, and a means for placing and spreading a couplant material between the ultrasonic transceiver (15) sole plate and said wall.

Description

A device and method for ultrasonic monitoring, measuring and tracking of a heat seal bead between two metal parts.

The present invention relates to a device and a method for measuring control and ultrasonic tracking of a heat seal bead between two metal parts.

In the context of mechanical engineering and for example in the context of the construction of nuclear reactors, metal parts are interconnected by a weld bead deposited by a head of a manual or automatic welding torch.

For some applications, the weld bead must be placed in a deep and narrow chamfer formed between the two parts to be joined. This is the case, for example, with the steam generators of the primary circuit circuits of nuclear reactors when it is necessary to assemble, on site, two parts of the replacement steam generator during the replacement operations of used steam generators.

Indeed, these replacement steam generators comprise an outer envelope formed of two parts, an upper part and a lower part, the upper part being attached to the lower part.

The upper part of the casing is connected to the lower part by butt welding of these two cylindrical tubular pieces of very large diameter whose connecting surfaces facing are substantially horizontal. These two parts form between them at their junction plane a narrow and deep welding chamfer and is directed horizontally.

The welding must be done manually or automatically by depositing successive layers of a filler metal along the width of the chamfer, until completely fill said chamfer. During the deposition of the different successive layers of the filler metal in the chamfer, it may occur, for various reasons, welding defects.

However, the junction welds of this kind of nuclear reactor components must not include any defects or at least no defects that may change over time during operation of the nuclear reactor. In order to remedy this kind of defects and to prevent weld seams from meeting the technical specifications, checks of the successive layers of the weld seam are carried out.

To carry out the control of welding defects between two metal parts, it is known to use an ultrasonic nondestructive test method of moving a source of emission of at least one ultrasonic beam onto an accessible surface of the parts in the vicinity. welding, so that the ultrasonic emission source directs an ultrasound beam towards the weld, in the thickness of the parts. Echo signals are collected and recorded which are due, among other things, to defects in the weld.

However, one of the main difficulties to be overcome lies in the high temperature that prevails in the vicinity of the weld and especially inside the chamfer and which is of the order of 150 to 250 ^° C. Given this constraint, the translators to ultrasound generally used, lose their effectiveness and sensitivity so that the detection of defects is limited and the reliability of controls reduced.

The object of the invention is to propose a device and a method making it possible, by means that are simple to implement, to monitor and control hot and precisely a weld bead between two metal parts and in particular a weld bead. the inside of a chamfer arranged between two metal parts.

The invention therefore relates to a device for monitoring, measuring and ultrasonic tracking of a hot-weld bead between two metal parts, of the type comprising at least one ultrasonic transducer, characterized in that it comprises a shoe provided with a flat face adapted to be in contact with a wall of one of the two parts and comprising:

a housing for maintaining said at least one ultrasound transducer in a predetermined orientation with respect to said wall, said at least one transducer comprising a support plate against this wall,

means for cooling said at least ultrasonic transducer to a temperature below its operating limit temperature, and - Means for removing and distributing a product coupling between the sole of said at least ultrasonic transducer and said wall. According to other features of the invention:

the device comprises means for longitudinally moving said at least ultrasonic transducer by means of the shoe on said wall in a direction parallel to the weld seam,

- the shoe has the shape of a rectangular parallelepiped,

the housing of the at least one ultrasound transducer is situated substantially in the center of the shoe, the cooling means comprise at least one network of channels for the circulation of a fluid, formed in the shoe and connected to an inlet and an outlet of said fluid; ,

the cooling means comprise two networks of channels for circulation of a fluid, formed in the shoe, said networks being arranged on either side of the housing and being connected to an inlet and an outlet of said fluid,

the means for depositing and distributing the coupling product comprise orifices opening onto the flat face of the shoe and connected to means for feeding said coupling product via channels formed in the shoe, and

- The device comprises means for removing the coupling product deposited on said wall and cleaning the wall after the passage of the shoe.

The subject of the invention is also a method for controlling, measuring and ultrasonically monitoring a hot-weld bead between two metal parts by means of a device as defined above, characterized in that it consists of the following steps: - the shoe is placed on the wall of one of the two parts by applying the flat face of this shoe to said wall,

the ultrasonic transducer is cooled by circulating the cooling fluid in the at least one channel network,

the coupling product is deposited on the wall by the orifices provided on the flat face of the shoe and this coupling product is distributed between the soleplate of the ultrasonic transducer and the said wall, and the ultrasonic transducer is moved longitudinally and parallel to the weld bead by means of the shoe to carry out the control, the measurement and the monitoring of the welding of this bead.

Other features and advantages of the invention will appear on reading the following description given by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic view in vertical section of a chamfer between two parts to be welded and in which is deposited a weld bead to be controlled by a device according to the invention; FIG. 2 is a schematic perspective view of a support shoe of an ultrasonic transducer of the device according to the invention,

FIG. 3 is a schematic perspective view from below of the shoe of FIG. 2

FIG. 4 is a diagrammatic perspective view in section along line 4-4 of FIG. 2

FIG. 5 is a schematic perspective view of a steam generator and an automatic welding device equipped with the control device, measuring and monitoring, according to the invention,

FIG. 6 is a schematic view on a larger scale of the automatic welding device equipped with the device according to the invention and

FIG. 7 is a schematic perspective view of an exemplary embodiment of an apparatus for supporting and moving the device according to the invention.

In FIG. 1, diagrammatically and partially shown two parts 1 and 2 to be joined having junction surfaces opposite that delimit between them a welding chamfer 3 of a precise and constant shape, along the entire length or the entire periphery parts 1 and 2 in which a weld bead 4 is produced.

For example, the parts 1 and 2 are made so as to bear against each other by bearing heels, respectively 1a and 1b, and the chamfer 3 can be a narrow chamfer whose side walls 5 and 6 of the parts 1 and 2 are between them a very small angle, for example less than 5 °, or are substantially parallel or between them a wide chamfer whose faces are at an angle of 5 ° to 90 °.

Depending on the application, the welding of parts 1 and 2 can be done horizontally flat or cornice, or vertically using a head of a welding torch not shown, manual or automatic. In addition, the welding can be rectilinear or orbital.

During the deposition of the successive layers of the filler metal in the chamfer 3, it can occur for various causes, for example a defect such as bite or gutter on the side walls or a collapse of the weld bead or a bad distribution of the metal contributed.

In order to correct this kind of defects and to avoid welding beads that do not meet the technical specifications, checks and measurements of the successive layers of the weld bead 4 are carried out by means of a device according to the invention and designated by the general reference 10. The device 10 is placed in contact with one of the outer walls 5 or

6 parts 1 or 2, such as the outer wall 6 and is intended to carry out the control, measurement and ultrasonic tracking of the weld bead 4 hot, either successive layers or the weld bead finished.

For this, the device 10 comprises a shoe 11 which is in the form of a metal block having the shape, for example of a rectangular parallelepiped.

As shown in Figs. 2 and 3, the shoe 11 has a flat face 12 intended to be applied to the outer wall 6 and a housing 13 having an opening 14 opening on the flat face 12. This housing 13 is intended to receive at least one ultrasonic transducer

Held in this housing 13 by suitable means such that said ultrasonic transducer 15 is positioned in a predetermined orientation with respect to the outer wall 6, as schematically shown in FIG. 1. The housing 13 may receive a plurality of ultrasonic transducers 15, one operating as an emitter and another operating as a receiver. The ultrasound transducer 15 comprises a sole 16 (FIG 3) which opens out at the opening 14 formed in the flat face 12 of the shoe 11.

The housing 13 for the ultrasound transducer 15 is located substantially in the center of the shoe 11.

In general, the shoe 11 also comprises:

means for cooling the ultrasonic transducer at a temperature below its operating limit temperature, and

- Means for removing and distributing a product coupling between the sole plate 16 of the ultrasonic transducer 15 and the outer wall 6.

The cooling means comprise at least one network 20 of channels 21 for circulating a cooling fluid and in the embodiment shown in FIGS. 2 to 4, two networks 20.

In FIG. 4, there is shown a single network 20 of channels 21, the other network 20 of channels 21 being identical and symmetrical with respect to the housing 13. Thus, the networks 20 are arranged on either side of the housing 13.

The channels 21 of each network 20 open at a first end 21a in a manifold 22 connected to a cooling fluid supply duct 23 and at a second end 21b in a manifold 24 connected to a duct 25 of output of this cooling fluid.

According to a variant, the cooling means are formed by an array of channels arranged around the housing 13 to ensure efficient cooling of the ultrasonic transducer 15.

The means for depositing and distributing the coupling product, for example a gel, comprise openings 30 opening on the flat face 12 of the shoe 11 (FIG 3) and connected by channels, not shown, formed in this shoe 11. at a port 31 for supplying the coupling product.

In the embodiment shown in FIG. 3, orifices 30 are arranged on either side of the opening 14, ie on either side of the sole plate 16 of the ultrasonic transducer 15.

The control of the weld bead 4 at a temperature of the order of 150 to 250 ^° C. is carried out as follows. First, the shoe 11 is connected to the cooling fluid supply means and to the coupling product supply means.

The shoe 11 is placed on one of the outer walls near the chamfer 3, for example the outer wall 6. The cooling fluid at a constant temperature between, for example, 9 and 15 ° C. is circulated in the channels 21 of the networks 20 so as to cool the ultrasonic transducer 15 to maintain it at a temperature below its operating limit temperature and in particular at a temperature below 150 ⁰ C. The shoe 10 is moved, either manually or automatically so autonomously by means of a specific tool, simultaneously with the movement of a welding torch head and the coupling product is deposited between the soleplate

16 of the ultrasound transducer 15 and the wall 6 during the movement of this shoe

11. This ultrasound transducer 15 is moved longitudinally and parallel to the weld bead 4 by means of the shoe 11 so as to carry out the control, measurement and monitoring of the weld of this bead.

Removal of the coupling product can be performed both during a control in forward and reverse control by moving the shoe 11 in one direction or the other.

The cooling of the ultrasound transducer 15 makes it possible to optimize its operation and to be able to obtain control and monitoring of the reliable and efficient hot solder bead.

After the passage of the shoe 1 1 on the side wall 6, the surface of this side wall 6 is cleaned by a suitable system. This system comprises for example a rotating brush which is itself cleaned for example by a splined shaft and this system can be combined with a system of compressed air jets to ensure optimal cleaning of the surface and the brush.

Referring now to Figs. 5 and 6, there will be described an example of use of the device 10 with an automatic welding torch head and cornice two tubular cylindrical pieces and large diameter of a nuclear reactor component, such as a generator of steam. In FIG. 5, there is shown a steam generator 35 whose outer casing is, in a conventional manner, composed of two parts, respectively 36 and 37 which are introduced separately into a casemate, the upper part 36 of the steam generator 35 being attached to the lower part 37 which has been put in place and previously connected to the primary circuit of the reactor.

To make the connection, the two parts 36 and 37 to be joined are placed end to end so as to have junction surfaces facing each other which are machined carefully in order to delimit between them a welding chamfer, not shown, of a precise and constant shape, along the entire periphery of the parts 36 and 37, according to which a weld bead is produced.

Achieving the weld bead between the parts 36 and 37 placed in a superimposed joint arrangement commonly referred to as the cornice expression, requires the use of a suitable welding device and moving and control means allowing perform fully automated welding operations with remote control, while ensuring perfect welding quality.

Such an automatic welding device generally designated 40 in FIG. 6, has been described in the French patent application No. 2,877,246. In this case, the automatic welding device 40 is associated with a device for monitoring, measuring and ultrasonic tracking of the heat seal bead, deposited inside the chamfer formed between the two parts 36 and 37.

As shown in FIG. 6, the automatic welding device designated by the general reference 40 is composed in particular of a welding head 41 and a rail 42 of circulation of this welding head 41. This rail is coaxial with the piece 36 and comprises on its outer face opposite to the one facing the piece

36, a rack 43.

This rail 42 consists of several sections juxtaposed and interconnected by appropriate means of conventional type, not shown, is fixed on the piece 36 by feet 44 uniformly distributed.

The displacement of the welding head 41 on the rail 42 around parts 36 and 37 is achieved by a carriage 45 carrying in particular the welding head 41 and equipped with rollers 46 arranged respectively on the upper edge and on the lower edge of the rail 42. The carriage 45 is moved by an electric motor, not shown, carried by this carriage and whose output shaft rotates a pinion , not shown, meshing with the rack 43 of the rail 42. The support assembly of the welding torch 41 comprises means

47 of moving this welding torch in the direction of the depth of the chamfer and also displacement in the direction of the width of this chamfer.

The head of the welding torch 41 comprises an anterior portion 50 intended to be introduced into the chamfer between the parts 36 and 37 and this head has a thickness substantially less than the width of this chamfer.

Conventionally, the welding torch 41 is fed by a filler wire, not shown, in which passes an electric current to achieve its fusion inside the chamfer by an electric arc. The filler metal wire is disposed on a storage coil 51 and a motorized device 52 supplies the welding torch 41 with filler wire.

As shown in FIG. 6, the head of the welding torch 41 is associated with a device 10 for monitoring, measuring and ultrasonic tracking of the heat seal bead inside the chamfer, formed between the parts 36 and 37.

This device 10 is identical to that described above and comprises a shoe 11 equipped with at least one ultrasound transducer 15. This device 10 is disposed downstream of the welding torch 41 with respect to its direction of movement in the chamfer and is , preferably associated with a cleaning system of the surface of the outer wall on which the shoe 11 has moved.

The device 10 has vertical and horizontal displacement means not shown in FIG. 6.

During displacement of the shoe 1 1, the ultrasonic transducer 15 is powered to emit an ultrasonic wave beam in a determined direction to perform a scan of the weld previously deposited in the chamfer. In the case where a fault is present, in an area of the weld, at a certain moment of the scanning, an echo signal representative of the defect is then emitted and displayed on a screen of an operating unit of the ultrasonic control.

During a test carried out simultaneously with the weld and downstream from it, and in the case where a defect is identified, it is possible, according to certain criteria, to warn an operator who stops the welding and implements corrective actions.

If the defect is considered to be small, the operator can decide to continue the deposition of the weld bead so that during the second pass to the next turn, this defect will be melted advantageously without requiring a stop and a local recovery of the weld seam.

In the case of automatic welding, it is possible to send orders to correct the welding parameters to the welding torch to avoid accentuating a drift to a poor quality of the weld bead which would then become out of criteria.

In FIG. 7, there is shown an example of an apparatus for supporting and moving the shoe 11 of the ultrasonic inspection device 10, associated with a cleaning system 70 of the face of the part on which this device will be moved. This support apparatus generally designated by the reference 60 comprises a carriage 61 provided with rollers 62 intended to cooperate with a rail, such as for example the rail 42 of FIG. 6.

The carriage 61 may be equipped with drive means on the rail 42 or may be moved manually or may be associated with the welding assembly described above.

The carriage 61 supports a set of arms 65 and in particular a horizontal arm 65a provided at its free end, the shoe 11 carrying said at least ultrasonic transducer and the cleaning system 70 for recovering the previously deposited coupling product. The arms 65 are provided with means 71, of known type, for example cylinders, screw / nut systems or any other system for moving the shoe 11 and the cleaning system 70 horizontally and / or vertically and also to rotate them in order to be able to adjust the position of said shoe and said cleaning system with respect to the face of the metal part or these elements must be positioned and moved.

The invention applies not only in the case of ultrasonic testing of welds of nuclear reactor components, but also in the case of any component of mechanical assemblies having welds between parts.

Claims

1.- Device for monitoring, measuring and ultrasonic tracking of a weld bead (4) hot between two metal parts (1, 2), of the type comprising at least one ultrasonic transducer (15), characterized in it comprises a shoe (11) provided with a flat face (12) adapted to be in contact with a wall of one of the two parts (1, 2) and comprising:

a housing (13) for holding said at least one ultrasonic transducer (15) in a predetermined orientation with respect to said wall, said at least one translator (15) comprising a sole (16) bearing against said wall, - means (20) cooling said at least ultrasonic transducer

(15) at a temperature below its operating limit temperature, and

- means (30) for depositing and distributing a product coupling between the sole (16) of said at least ultrasonic transducer (15) and said wall.

2. - Device according to claim 1, characterized in that it comprises means for longitudinal displacement of said at least ultrasonic transducer (15) by means of the shoe (11) on said wall in a direction parallel to the weld seam (4). ).

3. Device according to claim 1 or 2, characterized in that the shoe (11) has the shape of a rectangular parallelepiped.

4. Device according to any one of claims 1 to 3, characterized in that the housing (13) of said at least ultrasonic transducer (15) is located substantially in the center of the shoe (11).

5. Device according to any one of claims 1 to 4, characterized in that the cooling means comprise at least one network (20) of channels (21) for circulation of a fluid, formed in the shoe (1 1). and connected to an inlet (22, 23) and an outlet (24, 25) of said fluid.

6. Device according to any one of claims 1 to 5, characterized in that the cooling means comprise two networks (20) of channels (21) for circulation of a fluid, formed in the shoe (11), said networks. (20) being disposed on either side of the housing (13) and being connected to an inlet (22, 23) and an outlet (24, 25) of said fluid.

7. Device according to any one of claims 1 to 6, characterized in that the means for depositing and distributing the coupling product comprise openings (30) opening on the face (12) plane of the shoe (11) and connected to supply means of said coupling product through channels in the shoe (11).

8. Device according to any one of claims 1 to 7, characterized in that it comprises means (70) for removing the coupling product deposited on said wall and cleaning the wall after the passage of the shoe (11). .

9. A method for controlling, measuring and ultrasonically monitoring a weld bead (4) hot between two metal parts (1, 2) by means of a device according to any one of the preceding claims, characterized in that what it consists of the following steps:

- the shoe (11) is placed on the wall of one of the two parts (1, 2) by applying the flat face (12) of this shoe (11) to said wall,

- Cooling the ultrasonic transducer (15) by circulating the cooling fluid in said at least one network (20) of channels (21) - is deposited on the wall the product coupling through the orifices (30) formed on the face planar (12) of the shoe (11) and distributes this coupling product between the soleplate (16) of the ultrasonic transducer (15) and said wall, and

- The ultrasonic transducer (15) is moved longitudinally and parallel to the weld seam (4) by means of the shoe (11) to control, measure and monitor the weld of the cord.

10. The method of claim 9, characterized in that one removes the coupling product deposited on the wall and cleans the wall after the passage of the shoe (11).